Format of Denver Phone Numbers

In Denver and throughout the US, landline and mobile phones have identical 10-digit numbering formats.

There is no way to tell by looking at a written telephone number whether it is a landline number or a cell phone number. This contrasts with some countries where mobile numbers and landline numbers can be different.

When written, a Denver telephone number will almost always include all 10-digits required for dialing. This is because even when dialing within the US, even to a number just down the street, the entire 10-digit phone number must be dialed.

In some cases, you may find a Denver phone number written with 11-digits. In such case, the 11th digit will be a leading ' 1 ' which is used for both domestic long distance dialing and for inbound international dialing. United States is one of the few countries with the same country code and national direct dial (NDD) code.

The format of Denver phone numbers and all numbers throughout the US are governed by the North American Numbering Plan (NANP). A total of 18 other countries participate in the plan, in addition to the US.

Denver Landline Phone Numbers

Denver Landline Phone Number Format

Generally, a Denver landline phone number will be written with dashes and look like this: aaa-nnn-nnnn as in 303-509-6995. Phone numbers are also written equivalently as: (303) 509-6995.

In some cases, the 10-digit number will be preceded by a ' 1 ' signifying both the country code and domestic long distance code. For instance, 1-303-509-6995 or 1 (303) 509-6995.

Denver Landline Area Codes

Denver landline area codes are always 3-digits long and are almost always included in written phone numbers. Landline area codes are indistinguishable from mobile area codes.

In written phone numbers, it is not uncommon to see the area code preceded by a ' 1 ', as described above.

Like other large metropolitan areas in the US, Denver uses multiple area codes. Originally, any given area had a single unique area code, but as more and more numbers have been required, Denver has gone to an overlay system where new area codes are added within the same geographic footprint.

Denver Local Subscriber Numbers for Landlines

Landline Subscriber Codes for Major USA Carriers

Whereas in some countries it is fairly easy to determine what company issues what phone number, in the US this is not so easy - and, for the most part, not so necessary because detailed phone number information is usually readily available.

Denver Mobile Area Codes

Local Subscriber Numbers for Denver Mobiles

Just like landline numbers, moible subscriber numbers in Denver are always 7-digits long.

Mobile Subscriber Codes for Major USA Carriers

It is not readily possible to identify which USA mobile carrier has issued what phone number. And, because there is as yet no public mobile phone number directories published in the US, it can be as hard to track down a person's mobile number in the US as it is in many other countries.

That said, there are a number of paid services that offer reverse number lookup and/or cell phone number lookup to find Denver mobile customers.